Automatic block-signaling system for electric railways.



0. B. STEVENS. AUTOMATIC BLOCK SIGNALING SYSTEM FOR ELECTRIC RAILWAYS.

APPLICATION FILED DEC. 31, 1908.

Patented Apr. 21, 1914.

2 SHEETS-SHEET 1.

- INVENTOR Oscarfifflfeflem AT RNEY O. E. STEVENS.

AUTOMATIC BLOCK SIGNALING SYSTEM FOR ELECTRIC RAILWAYS.

APPLIOATION FILED DEC. a1, 1908.

1,094,104. Patented Apr. 21, 191;

2 SHEETS-SHEET 2.

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witmeooeo 8 H00 VL loz Y S x v attoznu OSCAR EGERTON UNITED STATES PATENT OFFICE.

STEVENS, or unwnonx, N. Y., ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, A CORPORATION or NEW YORK.

- AUTOMATIC BLOCK-SIGNALING SYSTEM FOR ELECTRIC RAILWA YS.

Specification of Letters Patent.

Patented Apr. 21, 1914.

' Application filed December 31, 1908'. Serial No. 470,212.

To all whom it may concern Be it known that I, OSCAR EGERTON STE- VENS, a citizen of the United States, residing at New York city, county and State of New York, have invented certain new and useful Improvements in Automatic Block-Signaling Systems for Electric Railways, ofwhich the following is a specification.

My invention relates to a system of electrically operated and controlled devices particularly applicable for use in railway electric signaling.

The object of my invention is to do away with, first, any mechanical or electrical connections between the trackway and the signaling apparatus, and second, to control the signals themselves by local current without using a make or break relay.

In practice it has been found that the majority of failures in signaling are due to faulty connections and the failure of the relay employed to make good contact.

The accompanying drawings will serve to illustrate my inventlon, in which Figure 1 is a diagrammatic illustration of my improved system as a whole. Figs. 2 and 3, longitudinal sections through the electro-responsive device and induction device used for controlling the signals, Fig. 2 illustratin the position of the sections of the coil 0 the induction device when a train is in a block section, and Fig. 3 illustrating the position of the sections of the coil when no train is in a block section. Fig. 4:, an elevation of the electro-responsive device looking from the left, and Fig. 5 a vertical section through the induction device.

In the drawings, 5 indicates a source of propulsion current which may be either direct or alternating, as desired, 6, a trolley wire or third rail arranged parallel with the railway. 7 8, track rails which are bonded together in the usual manner to form continuous return paths for the propulsion current to the propulsion generator 5. 9, crossbonds located at the ends of the block sections. These crossbonds may be of any type, such as have heretofore been used to segregate the track rails into block sections or to segregate and control the circulation of the signaling current within the limits of a block section. 10, a source of signaling current. The signaling current employed is preferably alternating in character. Where the propulsion current is alternating, the

signaling current should diifer from it, by well known characteristics according to the design of the relay devices used. 1112, signaling feeders arranged parallel with the trackway. Located in each block section is the prlmary coil of an energy transformer 13, the terminals of which are connected to the feeders 11 12. The secondary of this transformer is formed by the rails 7 8 and two bonds, 9, located at opposite ends of the block sections, the rails and bonds forming a closed track circuit. The primarycoil of the transformer 13 may be located at any convenient position in a block section, as is now well understood by signaling engineers. Also located in each block section is the secondary coil of a signaling transformer 14. It will be observed that the closed track circuit which forms the secondary of the ener transformer 13 serves as the primary 0011 of the signaling transformer 14. One or more signaling transformers may be used, depending upon the position of the energy transformer 13 in the block section.

15 indicates an electro-responsive device having the general characteristics of an induction motor, adapted as is well understood to be energized by either polyphase, displaced or split-phase currents. Manifestly any form of induction device may be employed, which will perform the function of the induction device disclosed, as hereinafter stated. The electro-responsive device (15) shown, is provided with a stator memher having two coils, 1(3-17, displaced in distance. The coil 16 is shown as connected to the secondary terminals of the signaling transformer 14, and the terminals of the other coil, 17 connected across the signaling feeders 11-12 and a rotor member 18, which may be of the usual squirrel-cage type. The rotor member 18, as is usual, is mounted upon a hollow shaft 19, adapted to rotate in suitable bearings.

Connected at one end to the rotor member 18 and at its other end to the supporting base for the electro-responsive device, is a sprin 20, which spring is adapted to be put under tension when the rotormember is rotated in the direction shown by the arrow, and which acts to restore the rotor member to its original position when the sists of two sections, A and B. The sec-- control of the actuating electric motor 24.-vv

The 0 eration of m improved system will be readily understood. The signaling current derlved from the generator 10 and transmitted through the primary of transformer 13 will induce a current in its secondary, which is formed by a-closed track circuit. The current induced in the closed track circuit will in turn induce a current in the secondary of the si naling transformer 14-, which current wil fiow through the stator coil 16 of the electro-responsive device 15. The current traversing this coil being displaced in phase from the current derived from the feeders 1112 traversing the coil 17, will normally rotate the rotor member 18 in the direction shown by the arrow and such rotation will be communicated through shaft 19'to the B section of the coil 22 and the core 23 upon which it is mounted, of the induction device 21.

When a'block section is unoccupied by a motor vehicle, as shown at the right and I left of Fig. 1, the position of the section B of coil 22 relative to section A, is that illustrated in Fig. 3. It will be observed upon reference to this figure, that when the sections of the coil are in such position, the

current derived from the feeders 11-12 will fiow through the sections in the same direction, with the effect of magnetizing the core 23 and setting up reactance, which will ,oppose the flow of current derived from the feeders 11-12 through thesolenoid 24, and thus permit the semaphore'25 to drop to the clear? position. When, however, a block section is occupied, as shown in the central block of Fig. 1, the position of the sections A and B of the coil 22 is that shown in Fig. 2, and the current derived from the feeders 1112 will flow through the said sections'in opposite directions. Thus the magnetic flux due to the current flowing in section A is neutralized by the magnetic flux due to the current flowing in section B, and the magnetism of the core will not be suflicient to seriously impede the flow of current from the feeders 11-12, which will traverse the solenoid 24, which in turn will attract its .core and carry the semaphore 25 to the 11- 12, including the solenoid magnet or electric motor 24. Further, that it is immaterial how the induction device is actuated to control the local circuit.

Having thus described my invention, I claim:

1. In a signal. system, a signal biased to one position, a permanently. closed circuit including a source of current and an electric motor, connections between the motor, and the signal whereby the signal will be moved from the biased position by an operation of the motor caused by current from the source, and means in series with said source and motor for preventing sufiicient flow of current to cause an operation of the motor, thus allowing the signal to move to the biased position by reason of its bias. 1

2. In" a signal system, a signal biased to one position, a source of current, an electric motor adapted for governing the signal, connections between the source of current and the motor, a reaotance device inserted in said connections comprising a magnetic core, a fixed coil and a movable coil, a track circuit, and means governed by the track circuit for moving the movable coil whereby the reactance of the circuit including the motor is changed and the signal is thereby governed.

In testimony whereof, I aflix my signature, in the presence of two witnesses.

OSCAR EGERTON STEVENS. 

